Do you mean Fruit Flies?
Make a DIY fly trap: Take a jar and pour in a teaspoon of apple cider vinegar, two tablespoons of water, and fruity-smelling dish soap. Cover the top of the jar with plastic wrap, tighten it with a rubber band, and lightly puncture part of it with toothpick-sized holes. Like the pushy uninvited guests they are, fruit flies will find their way into the jar. But they'll have a hard time finding a way out.